// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_BASE_USER_ACTIVITY_USER_ACTIVITY_OBSERVER_H_
#define UI_BASE_USER_ACTIVITY_USER_ACTIVITY_OBSERVER_H_

#include "base/macros.h"
#include "ui/base/ui_base_export.h"

namespace ui {
class Event;
}

namespace ui {

// Interface for classes that want to be notified about user activity.
// Implementations should register themselves with UserActivityDetector.
class UI_BASE_EXPORT UserActivityObserver {
public:
    // Invoked periodically while the user is active (i.e. generating input
    // events). |event| is the event that triggered the notification; it may
    // be NULL in some cases (e.g. testing or synthetic invocations).
    virtual void OnUserActivity(const ui::Event* event) = 0;

protected:
    UserActivityObserver() { }
    virtual ~UserActivityObserver() { }

    DISALLOW_COPY_AND_ASSIGN(UserActivityObserver);
};

} // namespace ui

#endif // UI_BASE_USER_ACTIVITY_USER_ACTIVITY_OBSERVER_H_
